What best practices should be followed when working with external functions or libraries in PHP scripts, such as those from third-party sources like SYMCON?

When working with external functions or libraries in PHP scripts, such as those from third-party sources like SYMCON, it is important to carefully review the documentation and follow best practices to ensure compatibility and security. This includes checking for any required dependencies, handling errors gracefully, and sanitizing input to prevent vulnerabilities.

// Example of using a function from a third-party library (e.g. SYMCON)
try {
    // Include the external library file
    require_once 'external_library.php';

    // Call the function from the external library
    $result = external_function($param1, $param2);

    // Process the result
    echo $result;
} catch (Exception $e) {
    // Handle any errors that may occur
    echo 'An error occurred: ' . $e->getMessage();
}